(HW_4_1) Define the following terms and answer the questions regarding
them:
Parameter
Estimator
Estimate
Bias
Precision
Can an estimator be unbiased, but imprecise? For the following data what
is an unbiased estimator of the population average? Compute the coresponding
estimate
[sample mean] and its precision [StdError(sample
mean)].
2
5
9
2
3
7
11
2
3
6
4
4
7
6
6
10
4
3
5
7
(HW_4_2) Compute the correlation coefficient, R(X,Y),
for the following data. Please do this by hand and show all of your work.
X
Y
1
0
3
1
5
4
7
7
9
8
(HW_4_3) Find the equiation of the line, l_{1}, passing through
the points (-3, 5) and (X=1, Y=2). Identify the slope, m_{1},
and Y-intercept, b_{1}, of the line. A line, l_{2},
is perpendicular
to l_{1} if its slope is -1/m_{1}.
Can you find the
equation of the line, l_{2}, perpendicular to l_{1},
which goes through
the point (X=0, Y=3). What are l_{2}'s slope, m_{2}, and
Y-intercept,
b_{2}?
\Ivo D. Dinov, Ph.D., Departments of Statistics and Neurology, UCLA
School of Medicine/